Wireguard IPv6 not working

Installing and Using OpenWrt Network and Wireless Configuration
13

I have changed some settings: now I have a separate firewall zone for the wireguard VPN and I have enabled masquerade on LAN so I can access all the LAN devices in 192.168.1.0/24 from the VPN.
On my Wireguard client if i set 0.0.0.0/0, ::/0 I can use IPv4 of my home network, but IPv6 is not working (neither the client IPv6 or the home IPv6).
I have a /64 dynamic prefix assigned by the ISP every 4 hours and I would like to allow the wireguard client to use one of the IPv6 of the LAN.
I don't know whether to assign this IP through DHCPv6 or SLAAC, but SLAAC is working on my LAN and i have the entire /64 prefix there (so i think i can't make it working)
I don't want to negatively impact the home LAN network.
Can someone help me? I read that i should enable IPv6 masquerading on wan zone (does this cause something negative to my existing LAN network?) and then add ULA source address. Where do i need to assign the ULA address? Do i need to enable relay mode of RA?

/etc/config/network

config interface 'loopback'
	option device 'lo'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'

config globals 'globals'
	option ula_prefix 'fd55:2a2c:3bff::/48'

config device
	option name 'br-lan'
	option type 'bridge'
	list ports 'lan'

config interface 'lan'
	option device 'br-lan'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'

config interface 'wan'
	option device 'wan'
	option proto 'dhcp'

config interface 'wan6'
	option device 'wan'
	option proto 'dhcpv6'

config interface 'LTE'
	option proto 'qmi'
	option device '/dev/cdc-wdm0'
	option apn 'internet.it'
	option auth 'none'
	option pdptype 'ipv4v6'

config interface 'wg0'
	option proto 'wireguard'
	option private_key '...'
	option listen_port '51820'
	list addresses '10.5.0.1/24'

config wireguard_wg0
	option description 'Lele-iPhone'
	option public_key '...'
	option route_allowed_ips '1'
	list allowed_ips '10.5.0.10/32'
	option endpoint_host 'IPV6 DDNS'

config wireguard_wg0
	option description 'MacBook-Air'
	option public_key '...'
	list allowed_ips '10.5.0.20/32'
	option route_allowed_ips '1'
	option endpoint_host 'IPV6 DDNS'

/etc/config/firewall


config defaults
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	option synflood_protect '1'
	option flow_offloading '1'
	option flow_offloading_hw '1'

config zone
	option name 'lan'
	option input 'ACCEPT'
	option output 'ACCEPT'
	option forward 'ACCEPT'
	list network 'lan'
	option masq '1'

config zone
	option name 'vpn'
	option input 'ACCEPT'
	option output 'ACCEPT'
	option forward 'ACCEPT'
	list network 'wg0'

config zone
	option name 'wan'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	option masq '1'
	option mtu_fix '1'
	list network 'wan'
	list network 'wan6'
	list network 'LTE'

config rule
	option name 'Allow-Wireguard'
	option family 'ipv6'
	list proto 'udp'
	option src 'wan'
	option dest_port '51820'
	option target 'ACCEPT'

config forwarding
	option src 'lan'
	option dest 'wan'

config forwarding
	option src 'vpn'
	option dest 'lan'

config forwarding
	option src 'vpn'
	option dest 'wan'

config forwarding
	option src 'lan'
	option dest 'vpn'

config forwarding
	option src 'wan'
	option dest 'vpn'